Electric-arc lamp.



PATENTED JAN. 10, 1905.

W. G. FISH.

ELECTRIC ARC LAMP.

APPLIOATION FILED JUNE 24,1901.

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Waler C. Fish by Mfg.

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UNITED STATES Patented January 10, 1905.

PATENT OEEIcE.

WALTER C. FISH, OF LYNN, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEIV YORK.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 779,539, dated January 10, 1905.

Application filed June 24, 1901. Serial No. 65,773.

To all whom it may concern.-

Beit known thatI, \VALT E C. FIsH, a citi- Zen of the United States, residing at Lynn, county of Essex, State of Massachusetts, have invented certain new and useful Improvements in Electric-Arc Lamps, of which the following is a specification.

My present invention relates to means for securing stability of operation of electric-arc lamps, and more particularly of those utilizing direct current, whereby satisfactory operation may be secured without the use of the usual steadying resistance. The waste of energy which ordinarily takes place in the stead ying resistance is thus eliminated and the efficiency of the lamp correspondingly increased.

The various novel features which constitute my invention I have particularly pointed out in the claims appended hereto and have described the same in detail in the following specification, which for convenience of understanding is to be takenin connection with the accompanying drawings, in which Figure 1 is a diagrammatic representation of a lamp embodying various features of my invention, and Fig. 2 a view of a modification of a part of the same.

At 1 is indicated a pair of solenoids which cooperate with a U-shaped core or armature 2. This armature is mechanically connected to a clutch rod or tube 3, carryingat its lower end the clutch 4, this clutch engaging in the usual manner a carbon or other electrode 5. The cooperating carbon or electrode is shown at 6, and the ends of both of these electrodes are inclosed Within an inclosing globe 7 in the usual manner. The upper ends of the core 2 carry, respectively, upwardly-projecting rods 8 and 9, joined at their upper ends to a crossbar 10, secured to one member 11 of a dashpot. The other member 12 of the dash-pot is fastened to some stationary portion of the lamp-frame. (Not here shown.) The clashpot serves the usual purpose of preventing too violent reciprocation of the core 2 and the parts carried thereby.

In order to secure stable operation of the lamp with the usual stead ying resistance omitted, it is necessary that the arc-controlling mechanism shall move easily and respond readily to slight variations of current. If any tendency to hunting or pumping arises, espe cially in starting the lamp, I have found that the same may be suppressed or greatly reduced by providing the reciprocating parts of the lamp with a mechanical device or devices attached thereto and having a natural period or periods of oscillation different from the approximate period of reciprocation of the arccontrolling mechanism as a whole. To this end I mount upon one of the rods 8 a small block 13, of metal, such as lead, this block being confined between a pair of springs 11 15. In a similar manner a block 16 is conlined between springs 17 and 18 on the companion rod 9. These springs 14 and 17 may be of difierent strengths and of ditferentnumbers of convolutions, so that the blocks 13 and 16 possess different natural periods of oscillation when set into motion.

hen current is passed through the lamp, the core 2 is drawn up suddenly, thereby putting the springs 15 and 18 under compression due to the inertia of the blocks 13 and 16, supported thereby. The blocks 13 and 16 are therefore caused to oscillate up and down on the rods 8 and 9, and due to the fact that their natural periods of oscillation are different from the period of movement of the armature 2 they act to break up any tendency toward a continued pumping or reciprocating of the armature 2 and its connected parts.

It is evident that the essential idea of my mechanical steadying device for arc-lamps may be embodied in a wide variety of constructions without departing from the spirit of my invention. Thus as an illustration the inertia devices might be suspended by tensionsprings, as shown at 2A in Fig. 2, instead of resting their weight on compressionsprings, such as 15 and 18 in Fig. 1. For the reason indicated my claims should not be limited to the constructions shown.

In addition to the mechanical means thus described for securing stability of operation I may in any case where it is desired employ a reactive coil in series with the lamp for opposing fluctuations in the current supplied to the lamp, and thereby securing greater sta bility of operation. This coil may be of any well-known type. I have found, however, that very superior results may be obtained by the use of the reactive coil indicated in the drawings, though the use of any reactive coil greatly assists the operation of the mechanical device above described. This reactive coil is indicated in diagram at 19 and consists of the core 20, having thereon two windings, a main or reactive winding 21, and a separate constantly-excited countermagnetizing-winding 22. The main winding 21 is in series with the lamp, as shown. The countermagnetizing-winding 22 is supplied with current from any suitable source as, for example, across the same mains that supply the lamp. This winding carries current suflicient to neutralize the magnetizing efl'ect of the reactive winding 21 when the current through the lamp is steady and of normal value. The magnetic flux in the core 20 is therefore zero under normal conditions. When, however, current in the lamp fluctuates, the current in the winding 21 varies up or down, as the case may be, and thereby sets up a strong magnetic flux. This flux produces a particularly powerful reactive effect upon the current fluctuations, due to the fact that the flux is varying through the Zero-point of the magnetization-curve, and therefore along the steepest portions of the same. This magnetization is especially prompt and vigorous, due to the fact that under these conditions the lag due to hysteresis is very much less than if the iron were worked at points higher up on the magnetization-curve.

It will be evident thatfluctuations of current in the winding 21 tend, as in a transformer, to set up corresponding fluctuations of current in the winding 22 inductively related thereto. In order to steady the current in the winding 22, I connect in series therewith a resistance 23. The electromotive forces introduced into the circuit of a winding 22 are caused thereby to have a less proportionate effect, and

, the current therein is consequently rendered steadier, the degree of smoothness obtainable being dependent upon the amount of this resistance and the proportions of the circuit as a whole, as will readily be understood by one skilled in the art.

What I claim as new, and desire to secure by Letters Patent of the United States, is

1. In an electric-arc lamp, the combination of an arc-controlling mechanism, devices possessinginertia carried by said mechanism, and means for allowing the said devices to oscillate freely relatively to said mechanism.

2. In an electricarc lamp,the combination of reciprocating arc-controlling mechanism, and a device or devices carried thereby so as to permit free oscillation and having a natural period of oscillation different from that of said mechanism.

3. In an electric-arc lamp, the combination of arc-controlling mechanism, a rod carried thereby, a pair of springs on said rod, and a device possessing inertia mounted between said springs and free to oscillate under the influence of impulses transmitted through said springs.

4:. In an electric-arc lamp, thecombination of arc-controlling mechanism, a rod carried thereby, a pair of springs confined between shoulders on said rod,and a device possessing inertia mounted on said rod between said springs and free to oscillate thereon.

5. The combination of an arc-lamp, an inductance-coil in series with said lamp, and mechanical means mounted to move bodily with the arc-controlling mechanism of the lamp and acting to oppose pumping or hunting of the same.

6. The combination with the arc-controlling mechanism of an arc-lamp, mechanical means mounted to move with said 21lC-COD- trollingmechanism and acting to oppose hunting or pumping of the same, and an inductance-coil in circuit with the lamp said inductance-coil being provided with a countermagnetizing-coil.

7. The combination with the arc-controlling mechanism of an arc-lamp, mechanical means mounted to move with said arc-controlling mechanism and acting to oppose hunting or pumping of the same an inductance-coil in circuit with the lamp,and means for main taining the flux in the core of said inductancecoil at or near the zero-point when normal current is flowing through the lamp.

8; In an electric-arc lamp, the combination of arc -controlling mechanism, and a supplemental device possesing considerable inertia connected to said mechanism through the intervention of a spring.

9. In an electric-arc lamp, the combination of arc-controlling mechanism, and a device or devices supplemental to said mechanism and operating by inertia to break up oscillation of said mechanism.

10. In an electric-arc lamp, the combination of arc-controlling mechanism, an inertia device or devices additional to said mechanism, and ayielding connection between said device or devices and said mechanism.

11. In an electric-arc lamp, the combination of arc-controlling mechanism, an inertia de-' vice or devices additional to said mechanism, anda resilient connection between said device or devices and said mechanism.

In witness whereof I have hereunto set my hand this 18th day of June, 1901.

\VALTER C. FISH.

Witnesses:

DUGALD MoK. MoKiLtor, JOHN J. WALKER.

IIS 

